Sustainability has become a central term in environmental planning and policy since the late 1980s. However, an understanding of landscapes in terms of sustainability is still poorly developed. The project Spatial Indices for Land Use Sustainability was conducted to elaborate spatially explicit indicators for mapping ecological sustainability. Ecological sustainability was defined in terms of naturalness and biodiversity. The concept of hemeroby, a measure for the naturalness or conversely the human influence on ecosystems, was used for the assessment of ecological sustainability. Because direct information on the hemerobiotic state of landscapes was missing, shortcuts were analysed. An interdisciplinary multi-scale approach was developed that combined remote sensing data and a landscape ecological field survey, using a landscape typology as spatial reference frame. Variables describing the configuration and shape of the land mosaic were derived form a land cover classification based on landform and landscape fragmentation data. Two different assessment approaches were compared, (a) an expert-knowledge based fuzzy-rule system, and (b) an assessment based on the deviation of a certain landscape type from the mean hemerobiotic state. The hemeroby model was formulated and applied using ordinal regression techniques. The project results support the ‘pattern and process paradigm’. Variables describing landscape patterns turned out to be crucial for the model and were a good predictor for land-use intensity estimated by the hemerobiotic state. Based on each of the two approaches a ‘sustainability map’ of Austria’s cultural landscapes was derived. Despite the methodological differences of the two approaches similarities in the results could be demonstrated. Landscape-structure indicators were shown to be good indicators of ecological sustainability because they are related to ecological characteristics of landscapes such as naturalness and biodiversity.